Iowa State Senate seat · lines in effect since 2022
Iowa Senate District 12
A district of about 63,000 people, 22% of adults with a bachelor's degree. It votes R+43.3 relative to the nation for president.
2024 election
Nov 5, 2024- Amy Sinclair (R) · won70.4%
- Nicole Loew (D)29.5%
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 12:13 PM ET
Where it sits among all 50 seats
Every Iowa State Senate seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Every election for this seat
16 races since 1968. District numbers are redrawn after each census: each group is one set of lines.
| Year | Winner | Runner-up | Won by |
|---|---|---|---|
| Lines first used in 2022 | |||
| 2024 | Amy Sinclair (R) | Nicole Loew (D) | 40.8 |
| Lines first used in 2012 | |||
| 2020 | Mark Costello (R) | Joseph Norris (D) | 38.2 |
| 2016 | Mark Costello (R) | Don W. Brantz (I) | 56.6 |
| 2012 | Joni Ernst (R) | — | Unopposed |
| Lines first used in 2002 | |||
| 2008 | Brian Schoenjahn (D) | Rebecca Wearmouth (R) | 28.7 |
| 2004 | Brian Schoenjahn (D) | Ron Longmuir (R) | 5.6 |
| Lines first used in 1992 | |||
| 2000 | Donald B. Redfern (R) | John A. Padget Jr. (D) | 19.1 |
| 1996 | Donald B. Redfern (R) | Michael James Carroll (D) | 14.2 |
| 1992 | Jerry Slafe (R) | — | Unopposed |
| Lines first used in 1982 | |||
| 1988 | Joy Corning (R) | Rose Angel (D) | 5.6 |
| 1984 | Joy Corning (R) | Ted Anderson (D) | 1.1 |
| Lines first used in 1972 | |||
| 1980 | Merlin D. Hulse (R) | Michael L. Richards (D) | 24.0 |
| 1976 | Merlin D. Hulse (R) | Paul Ponder (D) | 8.6 |
| 1972 | Clifton C. Lamborn (R) | Barbara Marland (D) | 22.3 |
| Lines first used in 1962 | |||
| 1970 | Alden J. Erskine (R) | Albert H. Gray (D) | 8.1 |
| 1968 | Joseph B. Flatt (R) | Jay E. Howe (D) | 31.0 |
Won by: the winner's lead over the runner-up, in points of the vote. Source: 99chambers results archive (MEDSL, Klarner, state election offices)
Districts that overlap District 12
The state's districts in other chambers that share residents with this one, and the share of District 12's area in each.
- U.S. House
- IA-3 100%
Every race on these lines
Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.
| 2024 | |
|---|---|
| President | R+41.0 |
Outlined: the race for this seat itselfBlank: no race that year
Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 8, 2026, 7:01 PM ET
Who lives here, compared
Grey bars show the spread of all 50 seats. Small marks are other seats in Iowa. The black marker is District 12.
Lower than 86% of seats.
Higher than 94% of seats.
Lower than 63% of seats.
Lower than 92% of seats.
Lower than 90% of seats.
Least dense of 50 seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean.
District 921% college gradsR+42.5Held RDistrict 5
25% college gradsR+40.2Held RDistrict 4
22% college gradsR+39.1Not up in 2026District 8
29% college gradsR+38.7Not up in 2026
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET